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        <h1 id="Netty"><a href="#Netty" class="headerlink" title="Netty"></a>Netty</h1><h2 id="简介"><a href="#简介" class="headerlink" title="简介"></a>简介</h2><p><a href="http://netty.io" target="_blank" rel="noopener">http://netty.io</a></p>
<p>Netty is an asynchronous event-driven network application framework<br>for rapid development of maintainable high performance protocol servers &amp; clients.</p>
<p>本系列源码在<br><a href="https://github.com/sail-y/netty" target="_blank" rel="noopener">https://github.com/sail-y/netty</a></p>
<h2 id="Netty能做什么？"><a href="#Netty能做什么？" class="headerlink" title="Netty能做什么？"></a>Netty能做什么？</h2><ol>
<li>可以像tomcat一样做一个http服务器。</li>
<li>socket开发。</li>
<li>支持长连接开发，例如websocket。</li>
</ol>
<a id="more"></a>
<h2 id="例子1-Http"><a href="#例子1-Http" class="headerlink" title="例子1: Http"></a>例子1: Http</h2><p>先忘记以前学过的servlet框架，netty并没有实现servlet的规范。</p>
<p>不多说，我们用netty先来写第一个例子，先跑起来试试看，后面再细说。</p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.firstexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.bootstrap.ServerBootstrap;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelFuture;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.EventLoopGroup;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.nio.NioEventLoopGroup;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.socket.nio.NioServerSocketChannel;</span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/20</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">TestServer</span> </span>&#123;</span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">        <span class="comment">// 分发任务</span></span><br><span class="line">        EventLoopGroup bossGroup = <span class="keyword">new</span> NioEventLoopGroup();</span><br><span class="line">        <span class="comment">// 实际处理的</span></span><br><span class="line">        EventLoopGroup workerGroup = <span class="keyword">new</span> NioEventLoopGroup();</span><br><span class="line">        <span class="keyword">try</span> &#123;</span><br><span class="line">            <span class="comment">// 启动服务</span></span><br><span class="line">            ServerBootstrap serverBootstrap = <span class="keyword">new</span> ServerBootstrap();</span><br><span class="line">            serverBootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)</span><br><span class="line">                    .childHandler(<span class="keyword">new</span> TestServerInitializer());</span><br><span class="line"></span><br><span class="line">            ChannelFuture channelFuture = serverBootstrap.bind(<span class="number">8899</span>).sync();</span><br><span class="line">            channelFuture.channel().closeFuture().sync();</span><br><span class="line"></span><br><span class="line">        &#125; <span class="keyword">finally</span> &#123;</span><br><span class="line">            bossGroup.shutdownGracefully();</span><br><span class="line">            workerGroup.shutdownGracefully();</span><br><span class="line">        &#125;</span><br><span class="line"></span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.firstexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelInitializer;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelPipeline;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.socket.SocketChannel;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.http.HttpServerCodec;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/20</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">TestServerInitializer</span> <span class="keyword">extends</span> <span class="title">ChannelInitializer</span>&lt;<span class="title">SocketChannel</span>&gt; </span>&#123;</span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">protected</span> <span class="keyword">void</span> <span class="title">initChannel</span><span class="params">(SocketChannel ch)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        ChannelPipeline pipeline = ch.pipeline();</span><br><span class="line">        pipeline.addLast(<span class="string">"httpServerCodec"</span>, <span class="keyword">new</span> HttpServerCodec());</span><br><span class="line">        pipeline.addLast(<span class="string">"testHttpServerHandler"</span>, <span class="keyword">new</span> TestHttpServerHandler());</span><br><span class="line"></span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.firstexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.buffer.ByteBuf;</span><br><span class="line"><span class="keyword">import</span> io.netty.buffer.Unpooled;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelHandlerContext;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.SimpleChannelInboundHandler;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.http.*;</span><br><span class="line"><span class="keyword">import</span> io.netty.util.CharsetUtil;</span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/20</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">TestHttpServerHandler</span> <span class="keyword">extends</span> <span class="title">SimpleChannelInboundHandler</span>&lt;<span class="title">HttpObject</span>&gt;</span>&#123;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">protected</span> <span class="keyword">void</span> <span class="title">channelRead0</span><span class="params">(ChannelHandlerContext ctx, HttpObject msg)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        ByteBuf content = Unpooled.copiedBuffer(<span class="string">"Hello World"</span>, CharsetUtil.UTF_8);</span><br><span class="line">        FullHttpResponse response = <span class="keyword">new</span> DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, content);</span><br><span class="line">        response.headers().set(HttpHeaderNames.CONTENT_TYPE, <span class="string">"text/plain"</span>);</span><br><span class="line">        response.headers().set(HttpHeaderNames.CONTENT_LENGTH, content.readableBytes());</span><br><span class="line"></span><br><span class="line">        ctx.writeAndFlush(response);</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p>虽然看起来复杂，但是几乎所有的netty程序的代码流程都是这样的。<br>定义好boss和worker的group-&gt;在childHandler定义ServerInitializer-&gt;在initChannel中定义通道处理器-&gt;实现通道处理器相应的回调方法。</p>
<p>注意loop group是死循环，必须手动停止，接下来我们来测试。</p>
<p>运行TestServer.</p>
<p>命令行测试</p>
<figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">curl localhost:8899</span><br></pre></td></tr></table></figure>
<p><img src="http://7xs4nh.com1.z0.glb.clouddn.com/%E5%B1%8F%E5%B9%95%E5%BF%AB%E7%85%A7%202017-05-20%20%E4%B8%8B%E5%8D%889.35.25.png" alt=""></p>
<p>接着我们看一下netty处理器的生命周期，改一下<code>TestHttpServerHandler</code>的代码。</p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br><span class="line">60</span><br><span class="line">61</span><br><span class="line">62</span><br><span class="line">63</span><br><span class="line">64</span><br><span class="line">65</span><br><span class="line">66</span><br><span class="line">67</span><br><span class="line">68</span><br><span class="line">69</span><br><span class="line">70</span><br><span class="line">71</span><br><span class="line">72</span><br><span class="line">73</span><br><span class="line">74</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.firstexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.buffer.ByteBuf;</span><br><span class="line"><span class="keyword">import</span> io.netty.buffer.Unpooled;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelHandlerContext;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.SimpleChannelInboundHandler;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.http.*;</span><br><span class="line"><span class="keyword">import</span> io.netty.util.CharsetUtil;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> java.net.URI;</span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/20</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">TestHttpServerHandler</span> <span class="keyword">extends</span> <span class="title">SimpleChannelInboundHandler</span>&lt;<span class="title">HttpObject</span>&gt; </span>&#123;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">protected</span> <span class="keyword">void</span> <span class="title">channelRead0</span><span class="params">(ChannelHandlerContext ctx, HttpObject msg)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line"></span><br><span class="line">        <span class="keyword">if</span> (msg <span class="keyword">instanceof</span> HttpRequest) &#123;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">            HttpRequest httpRequest = (HttpRequest) msg;</span><br><span class="line"></span><br><span class="line">            System.out.println(<span class="string">"请求方法名："</span> + httpRequest.method().name());</span><br><span class="line">            URI uri = <span class="keyword">new</span> URI(httpRequest.uri());</span><br><span class="line">            <span class="keyword">if</span> (<span class="string">"/favicon.ico"</span>.equals(uri.getPath())) &#123;</span><br><span class="line">                System.out.println(<span class="string">"请求favicon.ico"</span>);</span><br><span class="line">                <span class="keyword">return</span>;</span><br><span class="line">            &#125;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">            ByteBuf content = Unpooled.copiedBuffer(<span class="string">"Hello World"</span>, CharsetUtil.UTF_8);</span><br><span class="line">            FullHttpResponse response = <span class="keyword">new</span> DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, content);</span><br><span class="line">            response.headers().set(HttpHeaderNames.CONTENT_TYPE, <span class="string">"text/plain"</span>);</span><br><span class="line">            response.headers().set(HttpHeaderNames.CONTENT_LENGTH, content.readableBytes());</span><br><span class="line"></span><br><span class="line">            ctx.writeAndFlush(response);</span><br><span class="line">        &#125;</span><br><span class="line"></span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">channelActive</span><span class="params">(ChannelHandlerContext ctx)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        System.out.println(<span class="string">"channelActive"</span>);</span><br><span class="line">        <span class="keyword">super</span>.channelActive(ctx);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">channelRegistered</span><span class="params">(ChannelHandlerContext ctx)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        System.out.println(<span class="string">"channelRegistered"</span>);</span><br><span class="line">        <span class="keyword">super</span>.channelRegistered(ctx);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">handlerAdded</span><span class="params">(ChannelHandlerContext ctx)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        System.out.println(<span class="string">"handlerAdded"</span>);</span><br><span class="line">        <span class="keyword">super</span>.handlerAdded(ctx);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">channelInactive</span><span class="params">(ChannelHandlerContext ctx)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        System.out.println(<span class="string">"channelInactive"</span>);</span><br><span class="line">        <span class="keyword">super</span>.channelInactive(ctx);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">channelUnregistered</span><span class="params">(ChannelHandlerContext ctx)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        System.out.println(<span class="string">"channelUnregistered"</span>);</span><br><span class="line">        <span class="keyword">super</span>.channelUnregistered(ctx);</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p>这个代码用<code>curl</code>和浏览器访问得到的结果是不一样的，因为netty没有遵循servlet的规范，所以有些地方我们得自己处理。</p>
<p>这是<code>curl</code>工具的输出：<br><img src="http://7xs4nh.com1.z0.glb.clouddn.com/%E5%B1%8F%E5%B9%95%E5%BF%AB%E7%85%A7%202017-05-20%20%E4%B8%8B%E5%8D%8810.00.07.png" alt=""></p>
<p>这是浏览器第一次访问的输出：<br><img src="http://7xs4nh.com1.z0.glb.clouddn.com/%E5%B1%8F%E5%B9%95%E5%BF%AB%E7%85%A7%202017-05-20%20%E4%B8%8B%E5%8D%8810.04.29.png" alt=""></p>
<p>这是浏览器第二次访问的输出：<br><img src="http://7xs4nh.com1.z0.glb.clouddn.com/%E5%B1%8F%E5%B9%95%E5%BF%AB%E7%85%A7%202017-05-20%20%E4%B8%8B%E5%8D%8810.06.08.png" alt=""></p>
<p>那是因为<code>curl</code>每次请求完之后就断了。而在http1.1协议下，浏览器有一个keep-alive功能来决定服务端收到请求什么时候关闭这个连接。所以我在多等了一会后，服务器还是自动关闭了连接，控制台还是输出了<code>channelInactive</code>和<code>channelUnregistered</code></p>
<h2 id="例子2-Socket"><a href="#例子2-Socket" class="headerlink" title="例子2: Socket"></a>例子2: Socket</h2><p>代码演示</p>
<h3 id="server"><a href="#server" class="headerlink" title="server"></a>server</h3><p>先写server端代码</p>
<p><code>MyServer.java</code></p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.secondexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.bootstrap.ServerBootstrap;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelFuture;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.EventLoopGroup;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.nio.NioEventLoopGroup;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.socket.nio.NioServerSocketChannel;</span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> * 和第一个例子并没有太大的区别</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/22</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyServer</span> </span>&#123;</span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> <span class="keyword">throws</span> InterruptedException </span>&#123;</span><br><span class="line">        EventLoopGroup bossGroup = <span class="keyword">new</span> NioEventLoopGroup();</span><br><span class="line">        EventLoopGroup workerGroup = <span class="keyword">new</span> NioEventLoopGroup();</span><br><span class="line"></span><br><span class="line">        <span class="keyword">try</span> &#123;</span><br><span class="line">            ServerBootstrap serverBootstrap = <span class="keyword">new</span> ServerBootstrap();</span><br><span class="line">            serverBootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)</span><br><span class="line">                    .childHandler(<span class="keyword">new</span> MyServerInitializer());</span><br><span class="line"></span><br><span class="line">            ChannelFuture channelFuture = serverBootstrap.bind(<span class="number">8899</span>).sync();</span><br><span class="line">            channelFuture.channel().closeFuture().sync();</span><br><span class="line">        &#125; <span class="keyword">finally</span> &#123;</span><br><span class="line">            bossGroup.shutdownGracefully();</span><br><span class="line">            workerGroup.shutdownGracefully();</span><br><span class="line">        &#125;</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p><code>MyServerHandler.java</code></p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.secondexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelHandlerContext;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.SimpleChannelInboundHandler;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> java.util.UUID;</span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/22</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyServerHandler</span> <span class="keyword">extends</span> <span class="title">SimpleChannelInboundHandler</span>&lt;<span class="title">String</span>&gt;</span>&#123;</span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">protected</span> <span class="keyword">void</span> <span class="title">channelRead0</span><span class="params">(ChannelHandlerContext ctx, String msg)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        System.out.println(ctx.channel().remoteAddress() + <span class="string">", "</span> + msg);</span><br><span class="line">        ctx.channel().writeAndFlush(<span class="string">"from server: "</span> + UUID.randomUUID());</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="comment">/**</span></span><br><span class="line"><span class="comment">     * 如果出现异常，关闭连接</span></span><br><span class="line"><span class="comment">     */</span></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">exceptionCaught</span><span class="params">(ChannelHandlerContext ctx, Throwable cause)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        cause.printStackTrace();</span><br><span class="line">        ctx.close();</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p><code>MyServerInitializer .java</code></p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.secondexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelInitializer;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelPipeline;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.socket.SocketChannel;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.LengthFieldBasedFrameDecoder;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.LengthFieldPrepender;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.string.StringDecoder;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.string.StringEncoder;</span><br><span class="line"><span class="keyword">import</span> io.netty.util.CharsetUtil;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> *</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/22</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyServerInitializer</span> <span class="keyword">extends</span> <span class="title">ChannelInitializer</span>&lt;<span class="title">SocketChannel</span>&gt; </span>&#123;</span><br><span class="line"></span><br><span class="line">    <span class="comment">/**</span></span><br><span class="line"><span class="comment">     * 针对socket开发，我们处理的方式发生了一些变化</span></span><br><span class="line"><span class="comment">     */</span></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">protected</span> <span class="keyword">void</span> <span class="title">initChannel</span><span class="params">(SocketChannel ch)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        ChannelPipeline pipeline = ch.pipeline();</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> LengthFieldBasedFrameDecoder(Integer.MAX_VALUE, <span class="number">0</span>,<span class="number">4</span>,<span class="number">0</span>,<span class="number">4</span>));</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> LengthFieldPrepender(<span class="number">4</span>));</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> StringDecoder(CharsetUtil.UTF_8));</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> StringEncoder(CharsetUtil.UTF_8));</span><br><span class="line">        <span class="comment">// 最后添加我们自己的处理器</span></span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> MyServerHandler());</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<h2 id="client"><a href="#client" class="headerlink" title="client"></a>client</h2><p>客户端代码</p>
<p><code>MyClient.java</code></p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.secondexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.bootstrap.Bootstrap;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelFuture;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.EventLoopGroup;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.nio.NioEventLoopGroup;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.socket.nio.NioSocketChannel;</span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/22</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyClient</span> </span>&#123;</span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> <span class="keyword">throws</span> InterruptedException </span>&#123;</span><br><span class="line">        <span class="comment">// 客户端只需要一个EventLoopGroup</span></span><br><span class="line">        EventLoopGroup eventLoopGroup = <span class="keyword">new</span> NioEventLoopGroup();</span><br><span class="line"></span><br><span class="line">        <span class="keyword">try</span> &#123;</span><br><span class="line">            Bootstrap bootstrap = <span class="keyword">new</span> Bootstrap();</span><br><span class="line">            bootstrap.group(eventLoopGroup).channel(NioSocketChannel.class).handler(<span class="keyword">new</span> MyClientInitializer());</span><br><span class="line"></span><br><span class="line">            ChannelFuture channelFuture = bootstrap.connect(<span class="string">"localhost"</span>, <span class="number">8899</span>).sync();</span><br><span class="line">            channelFuture.channel().closeFuture().sync();</span><br><span class="line">        &#125;<span class="keyword">finally</span> &#123;</span><br><span class="line">            eventLoopGroup.shutdownGracefully();</span><br><span class="line">        &#125;</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p><code>MyClientHandler</code></p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.secondexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelHandler;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelHandlerContext;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.SimpleChannelInboundHandler;</span><br><span class="line"><span class="keyword">import</span> io.netty.util.concurrent.EventExecutorGroup;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> java.time.LocalDateTime;</span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/22</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyClientHandler</span> <span class="keyword">extends</span> <span class="title">SimpleChannelInboundHandler</span>&lt;<span class="title">String</span>&gt; </span>&#123;</span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">protected</span> <span class="keyword">void</span> <span class="title">channelRead0</span><span class="params">(ChannelHandlerContext ctx, String msg)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        System.out.println(ctx.channel().remoteAddress());</span><br><span class="line">        System.out.println(<span class="string">"client output: "</span> + msg);</span><br><span class="line">        ctx.writeAndFlush(<span class="string">"from clinet: "</span> + LocalDateTime.now());</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">exceptionCaught</span><span class="params">(ChannelHandlerContext ctx, Throwable cause)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        cause.printStackTrace();</span><br><span class="line">        ctx.close();</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="comment">/**</span></span><br><span class="line"><span class="comment">     * 如果不重写这个方法，运行程序后并不会触发数据的传输，因为双方都在等待read，所以要先发送一次消息。</span></span><br><span class="line"><span class="comment">     */</span></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">channelActive</span><span class="params">(ChannelHandlerContext ctx)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        ctx.channel().writeAndFlush(<span class="string">"1"</span>);</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p><code>MyClientInitializer.java</code></p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.secondexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelInitializer;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelPipeline;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.socket.SocketChannel;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.LengthFieldBasedFrameDecoder;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.LengthFieldPrepender;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.string.StringDecoder;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.string.StringEncoder;</span><br><span class="line"><span class="keyword">import</span> io.netty.util.CharsetUtil;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/22</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyClientInitializer</span> <span class="keyword">extends</span> <span class="title">ChannelInitializer</span>&lt;<span class="title">SocketChannel</span>&gt; </span>&#123;</span><br><span class="line"></span><br><span class="line">    <span class="comment">/**</span></span><br><span class="line"><span class="comment">     * 除了最后一行，跟服务端代码是一样的</span></span><br><span class="line"><span class="comment">     * <span class="doctag">@param</span> ch</span></span><br><span class="line"><span class="comment">     * <span class="doctag">@throws</span> Exception</span></span><br><span class="line"><span class="comment">     */</span></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">protected</span> <span class="keyword">void</span> <span class="title">initChannel</span><span class="params">(SocketChannel ch)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        ChannelPipeline pipeline = ch.pipeline();</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> LengthFieldBasedFrameDecoder(Integer.MAX_VALUE, <span class="number">0</span>,<span class="number">4</span>,<span class="number">0</span>,<span class="number">4</span>));</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> LengthFieldPrepender(<span class="number">4</span>));</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> StringDecoder(CharsetUtil.UTF_8));</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> StringEncoder(CharsetUtil.UTF_8));</span><br><span class="line">        <span class="comment">// 最后添加我们自己的处理器</span></span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> MyClientHandler());</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<h2 id="例子3：聊天"><a href="#例子3：聊天" class="headerlink" title="例子3：聊天"></a>例子3：聊天</h2><p>下面做一个简单的消息广播，服务端1个，客户端3个，每个客户端上线的时候，服务端就对每个客户端广播上线的消息，下线同理。客户端发送消息的时候，服务端也会对每一个客户端进行广播。</p>
<p><code>MyChatServer.java</code></p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.thirdexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.bootstrap.ServerBootstrap;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelFuture;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.EventLoopGroup;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.nio.NioEventLoopGroup;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.socket.nio.NioServerSocketChannel;</span><br><span class="line"></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyChatServer</span> </span>&#123;</span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> <span class="keyword">throws</span> InterruptedException </span>&#123;</span><br><span class="line">        EventLoopGroup bossGroup = <span class="keyword">new</span> NioEventLoopGroup();</span><br><span class="line">        EventLoopGroup workerGroup = <span class="keyword">new</span> NioEventLoopGroup();</span><br><span class="line"></span><br><span class="line">        <span class="keyword">try</span> &#123;</span><br><span class="line">            ServerBootstrap serverBootstrap = <span class="keyword">new</span> ServerBootstrap();</span><br><span class="line">            serverBootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)</span><br><span class="line">                    .childHandler(<span class="keyword">new</span> MyChatServerInitializer());</span><br><span class="line"></span><br><span class="line">            ChannelFuture channelFuture = serverBootstrap.bind(<span class="number">8899</span>).sync();</span><br><span class="line">            channelFuture.channel().closeFuture().sync();</span><br><span class="line">        &#125; <span class="keyword">finally</span> &#123;</span><br><span class="line">            bossGroup.shutdownGracefully();</span><br><span class="line">            workerGroup.shutdownGracefully();</span><br><span class="line">        &#125;</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p><code>MyChatServerHandler.java</code></p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br><span class="line">60</span><br><span class="line">61</span><br><span class="line">62</span><br><span class="line">63</span><br><span class="line">64</span><br><span class="line">65</span><br><span class="line">66</span><br><span class="line">67</span><br><span class="line">68</span><br><span class="line">69</span><br><span class="line">70</span><br><span class="line">71</span><br><span class="line">72</span><br><span class="line">73</span><br><span class="line">74</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.thirdexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.channel.Channel;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelHandlerContext;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.SimpleChannelInboundHandler;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.group.ChannelGroup;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.group.DefaultChannelGroup;</span><br><span class="line"><span class="keyword">import</span> io.netty.util.concurrent.GlobalEventExecutor;</span><br><span class="line"></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyChatServerHandler</span> <span class="keyword">extends</span> <span class="title">SimpleChannelInboundHandler</span>&lt;<span class="title">String</span>&gt; </span>&#123;</span><br><span class="line"></span><br><span class="line">    <span class="keyword">private</span> <span class="keyword">static</span> ChannelGroup channelGroup = <span class="keyword">new</span> DefaultChannelGroup(GlobalEventExecutor.INSTANCE);</span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">protected</span> <span class="keyword">void</span> <span class="title">channelRead0</span><span class="params">(ChannelHandlerContext ctx, String msg)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        Channel channel = ctx.channel();</span><br><span class="line"></span><br><span class="line">        channelGroup.forEach(ch -&gt; &#123;</span><br><span class="line">            <span class="keyword">if</span> (channel != ch) &#123;</span><br><span class="line">                ch.writeAndFlush(channel.remoteAddress() + <span class="string">" 发送的消息："</span> + msg + <span class="string">"\n"</span>);</span><br><span class="line">            &#125; <span class="keyword">else</span> &#123;</span><br><span class="line">                ch.writeAndFlush(<span class="string">"【自己】 "</span> + msg + <span class="string">"\n"</span>);</span><br><span class="line">            &#125;</span><br><span class="line">        &#125;);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="comment">/**</span></span><br><span class="line"><span class="comment">     * 如果出现异常，关闭连接</span></span><br><span class="line"><span class="comment">     */</span></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">exceptionCaught</span><span class="params">(ChannelHandlerContext ctx, Throwable cause)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        cause.printStackTrace();</span><br><span class="line">        ctx.close();</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">    <span class="comment">/**</span></span><br><span class="line"><span class="comment">     * 每一个客户端连接的时候，就保存它。</span></span><br><span class="line"><span class="comment">     */</span></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">handlerAdded</span><span class="params">(ChannelHandlerContext ctx)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        Channel channel = ctx.channel();</span><br><span class="line"></span><br><span class="line">        <span class="comment">// 在添加之前做一个广播</span></span><br><span class="line">        channelGroup.writeAndFlush(<span class="string">"【服务器】 - "</span> + channel.remoteAddress() + <span class="string">" 加入\n"</span>);</span><br><span class="line"></span><br><span class="line">        channelGroup.add(channel);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">handlerRemoved</span><span class="params">(ChannelHandlerContext ctx)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        Channel channel = ctx.channel();</span><br><span class="line"></span><br><span class="line">        <span class="comment">// 在移除之前做一个广播</span></span><br><span class="line">        channelGroup.writeAndFlush(<span class="string">"【服务器】 - "</span> + channel.remoteAddress() + <span class="string">" 离开\n"</span>);</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">        <span class="comment">// 这个代码在handlerRemoved的时候会自动的从group中移除，所以我们不用写。</span></span><br><span class="line">        <span class="comment">// channelGroup.remove(channel);</span></span><br><span class="line"></span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">channelActive</span><span class="params">(ChannelHandlerContext ctx)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        Channel channel = ctx.channel();</span><br><span class="line">        System.out.println(channel.remoteAddress() + <span class="string">" 上线"</span>);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">channelInactive</span><span class="params">(ChannelHandlerContext ctx)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        Channel channel = ctx.channel();</span><br><span class="line">        System.out.println(channel.remoteAddress() + <span class="string">" 下线"</span>);</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p><code>MyChatServerInitializer.java</code></p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.thirdexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelInitializer;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelPipeline;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.socket.SocketChannel;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.DelimiterBasedFrameDecoder;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.Delimiters;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.string.StringDecoder;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.string.StringEncoder;</span><br><span class="line"><span class="keyword">import</span> io.netty.util.CharsetUtil;</span><br><span class="line"></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyChatServerInitializer</span> <span class="keyword">extends</span> <span class="title">ChannelInitializer</span>&lt;<span class="title">SocketChannel</span>&gt; </span>&#123;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">protected</span> <span class="keyword">void</span> <span class="title">initChannel</span><span class="params">(SocketChannel ch)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        ChannelPipeline pipeline = ch.pipeline();</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> DelimiterBasedFrameDecoder(<span class="number">4096</span>, Delimiters.lineDelimiter()));</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> StringDecoder(CharsetUtil.UTF_8));</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> StringEncoder(CharsetUtil.UTF_8));</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> MyChatServerHandler());</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p><code>MyChatClient.java</code></p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.thirdexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> com.sail.netty.secondexample.MyClientInitializer;</span><br><span class="line"><span class="keyword">import</span> io.netty.bootstrap.Bootstrap;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.Channel;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelFuture;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.EventLoopGroup;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.nio.NioEventLoopGroup;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.socket.nio.NioSocketChannel;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> java.io.BufferedReader;</span><br><span class="line"><span class="keyword">import</span> java.io.IOException;</span><br><span class="line"><span class="keyword">import</span> java.io.InputStreamReader;</span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/22</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyChatClient</span> </span>&#123;</span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        <span class="comment">// 客户端只需要一个EventLoopGroup</span></span><br><span class="line">        EventLoopGroup eventLoopGroup = <span class="keyword">new</span> NioEventLoopGroup();</span><br><span class="line"></span><br><span class="line">        <span class="keyword">try</span> &#123;</span><br><span class="line">            Bootstrap bootstrap = <span class="keyword">new</span> Bootstrap();</span><br><span class="line">            bootstrap.group(eventLoopGroup).channel(NioSocketChannel.class).handler(<span class="keyword">new</span> MyChatClientInitializer());</span><br><span class="line"></span><br><span class="line">            Channel channel = bootstrap.connect(<span class="string">"localhost"</span>, <span class="number">8899</span>).sync().channel();</span><br><span class="line">            <span class="comment">// channel.closeFuture().sync();</span></span><br><span class="line"></span><br><span class="line">            <span class="comment">// 写一个死循环不断的去读取用户在控制台的输入</span></span><br><span class="line"></span><br><span class="line">            BufferedReader br = <span class="keyword">new</span> BufferedReader(<span class="keyword">new</span> InputStreamReader(System.in));</span><br><span class="line"></span><br><span class="line">            <span class="keyword">for</span> (;;) &#123;</span><br><span class="line">                channel.writeAndFlush(br.readLine() + <span class="string">"\r\n"</span>);</span><br><span class="line">            &#125;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line"></span><br><span class="line"></span><br><span class="line">        &#125;<span class="keyword">finally</span> &#123;</span><br><span class="line">            eventLoopGroup.shutdownGracefully();</span><br><span class="line">        &#125;</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p><code>MyChatClientHandler.java</code></p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.thirdexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelHandler;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelHandlerContext;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.SimpleChannelInboundHandler;</span><br><span class="line"><span class="keyword">import</span> io.netty.util.concurrent.EventExecutorGroup;</span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/22</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyChatClientHandler</span> <span class="keyword">extends</span> <span class="title">SimpleChannelInboundHandler</span>&lt;<span class="title">String</span>&gt; </span>&#123;</span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">protected</span> <span class="keyword">void</span> <span class="title">channelRead0</span><span class="params">(ChannelHandlerContext ctx, String msg)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        System.out.println(msg);</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p><code>MyChatClientInitializer.java</code></p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.thirdexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelInitializer;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelPipeline;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.socket.SocketChannel;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.DelimiterBasedFrameDecoder;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.Delimiters;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.string.StringDecoder;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.codec.string.StringEncoder;</span><br><span class="line"><span class="keyword">import</span> io.netty.util.CharsetUtil;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/22</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyChatClientInitializer</span> <span class="keyword">extends</span> <span class="title">ChannelInitializer</span>&lt;<span class="title">SocketChannel</span>&gt; </span>&#123;</span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">protected</span> <span class="keyword">void</span> <span class="title">initChannel</span><span class="params">(SocketChannel ch)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        ChannelPipeline pipeline = ch.pipeline();</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> DelimiterBasedFrameDecoder(<span class="number">4096</span>, Delimiters.lineDelimiter()));</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> StringDecoder(CharsetUtil.UTF_8));</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> StringEncoder(CharsetUtil.UTF_8));</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> MyChatClientHandler());</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<h2 id="例子4：heartbeat（心跳）"><a href="#例子4：heartbeat（心跳）" class="headerlink" title="例子4：heartbeat（心跳）"></a>例子4：heartbeat（心跳）</h2><p>下面演示一个集群中常见的心跳用netty的实现方式。</p>
<p><code>MyServer.java</code></p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.forthexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.bootstrap.ServerBootstrap;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelFuture;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.EventLoopGroup;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.nio.NioEventLoopGroup;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.socket.nio.NioServerSocketChannel;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.logging.LogLevel;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.logging.LoggingHandler;</span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> * 心跳检测的Netty实现</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/22</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyServer</span> </span>&#123;</span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        EventLoopGroup bossGroup = <span class="keyword">new</span> NioEventLoopGroup();</span><br><span class="line">        EventLoopGroup workerGroup = <span class="keyword">new</span> NioEventLoopGroup();</span><br><span class="line"></span><br><span class="line">        <span class="keyword">try</span> &#123;</span><br><span class="line">            ServerBootstrap serverBootstrap = <span class="keyword">new</span> ServerBootstrap();</span><br><span class="line">            serverBootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)</span><br><span class="line">                    <span class="comment">// handler是针对于bossGroup的</span></span><br><span class="line">                    .handler(<span class="keyword">new</span> LoggingHandler(LogLevel.INFO))</span><br><span class="line">                    <span class="comment">// childHandler是针对于workerGroup的</span></span><br><span class="line">                    .childHandler(<span class="keyword">new</span> MyServerInitializer());</span><br><span class="line"></span><br><span class="line">            ChannelFuture channelFuture = serverBootstrap.bind(<span class="number">8899</span>).sync();</span><br><span class="line">            channelFuture.channel().closeFuture().sync();</span><br><span class="line">        &#125; <span class="keyword">finally</span> &#123;</span><br><span class="line">            bossGroup.shutdownGracefully();</span><br><span class="line">            workerGroup.shutdownGracefully();</span><br><span class="line">        &#125;</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p><code>MyServerHandler.java</code></p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.forthexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelHandlerContext;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelInboundHandlerAdapter;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.timeout.IdleStateEvent;</span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/22</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyServerHandler</span> <span class="keyword">extends</span> <span class="title">ChannelInboundHandlerAdapter</span> </span>&#123;</span><br><span class="line"></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">userEventTriggered</span><span class="params">(ChannelHandlerContext ctx, Object evt)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        <span class="keyword">if</span> (evt <span class="keyword">instanceof</span> IdleStateEvent) &#123;</span><br><span class="line">            IdleStateEvent event = (IdleStateEvent) evt;</span><br><span class="line">            String eventType = <span class="keyword">null</span>;</span><br><span class="line"></span><br><span class="line">            <span class="keyword">switch</span> (event.state()) &#123;</span><br><span class="line"></span><br><span class="line">                <span class="keyword">case</span> READER_IDLE:</span><br><span class="line">                    eventType = <span class="string">"读空闲"</span>;</span><br><span class="line">                    <span class="keyword">break</span>;</span><br><span class="line">                <span class="keyword">case</span> WRITER_IDLE:</span><br><span class="line">                    eventType = <span class="string">"写空闲"</span>;</span><br><span class="line">                    <span class="keyword">break</span>;</span><br><span class="line">                <span class="keyword">case</span> ALL_IDLE:</span><br><span class="line">                    eventType = <span class="string">"读写空闲"</span>;</span><br><span class="line">                    <span class="keyword">break</span>;</span><br><span class="line">            &#125;</span><br><span class="line"></span><br><span class="line">            System.out.println(ctx.channel().remoteAddress() + <span class="string">" 超时事件： "</span> + eventType);</span><br><span class="line"></span><br><span class="line">            ctx.channel().close();</span><br><span class="line">        &#125;</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p><code>MyServerInitializer.java</code></p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.sail.netty.forthexample;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelInitializer;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.ChannelPipeline;</span><br><span class="line"><span class="keyword">import</span> io.netty.channel.socket.SocketChannel;</span><br><span class="line"><span class="keyword">import</span> io.netty.handler.timeout.IdleStateHandler;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> java.util.concurrent.TimeUnit;</span><br><span class="line"></span><br><span class="line"><span class="comment">/**</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@author</span> yangfan</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@date</span> 2017/05/22</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyServerInitializer</span> <span class="keyword">extends</span> <span class="title">ChannelInitializer</span>&lt;<span class="title">SocketChannel</span>&gt; </span>&#123;</span><br><span class="line"></span><br><span class="line">    <span class="comment">/**</span></span><br><span class="line"><span class="comment">     * IdleStateHandler可以检测连接的3种状态</span></span><br><span class="line"><span class="comment">     */</span></span><br><span class="line">    <span class="meta">@Override</span></span><br><span class="line">    <span class="function"><span class="keyword">protected</span> <span class="keyword">void</span> <span class="title">initChannel</span><span class="params">(SocketChannel ch)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">        ChannelPipeline pipeline = ch.pipeline();</span><br><span class="line"></span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> IdleStateHandler(<span class="number">5</span>, <span class="number">7</span>, <span class="number">3</span>, TimeUnit.SECONDS));</span><br><span class="line">        pipeline.addLast(<span class="keyword">new</span> MyServerHandler());</span><br><span class="line"></span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>

      
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              <div class="post-toc-content"><ol class="nav"><li class="nav-item nav-level-1"><a class="nav-link" href="#Netty"><span class="nav-number">1.</span> <span class="nav-text">Netty</span></a><ol class="nav-child"><li class="nav-item nav-level-2"><a class="nav-link" href="#简介"><span class="nav-number">1.1.</span> <span class="nav-text">简介</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#Netty能做什么？"><span class="nav-number">1.2.</span> <span class="nav-text">Netty能做什么？</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#例子1-Http"><span class="nav-number">1.3.</span> <span class="nav-text">例子1: Http</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#例子2-Socket"><span class="nav-number">1.4.</span> <span class="nav-text">例子2: Socket</span></a><ol class="nav-child"><li class="nav-item nav-level-3"><a class="nav-link" href="#server"><span class="nav-number">1.4.1.</span> <span class="nav-text">server</span></a></li></ol></li><li class="nav-item nav-level-2"><a class="nav-link" href="#client"><span class="nav-number">1.5.</span> <span class="nav-text">client</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#例子3：聊天"><span class="nav-number">1.6.</span> <span class="nav-text">例子3：聊天</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#例子4：heartbeat（心跳）"><span class="nav-number">1.7.</span> <span class="nav-text">例子4：heartbeat（心跳）</span></a></li></ol></li></ol></div>
            

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    }

    function proceedsearch() {
      $("body")
        .append('<div class="search-popup-overlay local-search-pop-overlay"></div>')
        .css('overflow', 'hidden');
      $('.search-popup-overlay').click(onPopupClose);
      $('.popup').toggle();
      var $localSearchInput = $('#local-search-input');
      $localSearchInput.attr("autocapitalize", "none");
      $localSearchInput.attr("autocorrect", "off");
      $localSearchInput.focus();
    }

    // search function;
    var searchFunc = function(path, search_id, content_id) {
      'use strict';

      // start loading animation
      $("body")
        .append('<div class="search-popup-overlay local-search-pop-overlay">' +
          '<div id="search-loading-icon">' +
          '<i class="fa fa-spinner fa-pulse fa-5x fa-fw"></i>' +
          '</div>' +
          '</div>')
        .css('overflow', 'hidden');
      $("#search-loading-icon").css('margin', '20% auto 0 auto').css('text-align', 'center');

      

      $.ajax({
        url: path,
        dataType: isXml ? "xml" : "json",
        async: true,
        success: function(res) {
          // get the contents from search data
          isfetched = true;
          $('.popup').detach().appendTo('.header-inner');
          var datas = isXml ? $("entry", res).map(function() {
            return {
              title: $("title", this).text(),
              content: $("content",this).text(),
              url: $("url" , this).text()
            };
          }).get() : res;
          var input = document.getElementById(search_id);
          var resultContent = document.getElementById(content_id);
          var inputEventFunction = function() {
            var searchText = input.value.trim().toLowerCase();
            var keywords = searchText.split(/[\s\-]+/);
            if (keywords.length > 1) {
              keywords.push(searchText);
            }
            var resultItems = [];
            if (searchText.length > 0) {
              // perform local searching
              datas.forEach(function(data) {
                var isMatch = false;
                var hitCount = 0;
                var searchTextCount = 0;
                var title = data.title.trim();
                var titleInLowerCase = title.toLowerCase();
                var content = data.content.trim().replace(/<[^>]+>/g,"");
                
                var contentInLowerCase = content.toLowerCase();
                var articleUrl = decodeURIComponent(data.url);
                var indexOfTitle = [];
                var indexOfContent = [];
                // only match articles with not empty titles
                if(title != '') {
                  keywords.forEach(function(keyword) {
                    function getIndexByWord(word, text, caseSensitive) {
                      var wordLen = word.length;
                      if (wordLen === 0) {
                        return [];
                      }
                      var startPosition = 0, position = [], index = [];
                      if (!caseSensitive) {
                        text = text.toLowerCase();
                        word = word.toLowerCase();
                      }
                      while ((position = text.indexOf(word, startPosition)) > -1) {
                        index.push({position: position, word: word});
                        startPosition = position + wordLen;
                      }
                      return index;
                    }

                    indexOfTitle = indexOfTitle.concat(getIndexByWord(keyword, titleInLowerCase, false));
                    indexOfContent = indexOfContent.concat(getIndexByWord(keyword, contentInLowerCase, false));
                  });
                  if (indexOfTitle.length > 0 || indexOfContent.length > 0) {
                    isMatch = true;
                    hitCount = indexOfTitle.length + indexOfContent.length;
                  }
                }

                // show search results

                if (isMatch) {
                  // sort index by position of keyword

                  [indexOfTitle, indexOfContent].forEach(function (index) {
                    index.sort(function (itemLeft, itemRight) {
                      if (itemRight.position !== itemLeft.position) {
                        return itemRight.position - itemLeft.position;
                      } else {
                        return itemLeft.word.length - itemRight.word.length;
                      }
                    });
                  });

                  // merge hits into slices

                  function mergeIntoSlice(text, start, end, index) {
                    var item = index[index.length - 1];
                    var position = item.position;
                    var word = item.word;
                    var hits = [];
                    var searchTextCountInSlice = 0;
                    while (position + word.length <= end && index.length != 0) {
                      if (word === searchText) {
                        searchTextCountInSlice++;
                      }
                      hits.push({position: position, length: word.length});
                      var wordEnd = position + word.length;

                      // move to next position of hit

                      index.pop();
                      while (index.length != 0) {
                        item = index[index.length - 1];
                        position = item.position;
                        word = item.word;
                        if (wordEnd > position) {
                          index.pop();
                        } else {
                          break;
                        }
                      }
                    }
                    searchTextCount += searchTextCountInSlice;
                    return {
                      hits: hits,
                      start: start,
                      end: end,
                      searchTextCount: searchTextCountInSlice
                    };
                  }

                  var slicesOfTitle = [];
                  if (indexOfTitle.length != 0) {
                    slicesOfTitle.push(mergeIntoSlice(title, 0, title.length, indexOfTitle));
                  }

                  var slicesOfContent = [];
                  while (indexOfContent.length != 0) {
                    var item = indexOfContent[indexOfContent.length - 1];
                    var position = item.position;
                    var word = item.word;
                    // cut out 100 characters
                    var start = position - 20;
                    var end = position + 80;
                    if(start < 0){
                      start = 0;
                    }
                    if (end < position + word.length) {
                      end = position + word.length;
                    }
                    if(end > content.length){
                      end = content.length;
                    }
                    slicesOfContent.push(mergeIntoSlice(content, start, end, indexOfContent));
                  }

                  // sort slices in content by search text's count and hits' count

                  slicesOfContent.sort(function (sliceLeft, sliceRight) {
                    if (sliceLeft.searchTextCount !== sliceRight.searchTextCount) {
                      return sliceRight.searchTextCount - sliceLeft.searchTextCount;
                    } else if (sliceLeft.hits.length !== sliceRight.hits.length) {
                      return sliceRight.hits.length - sliceLeft.hits.length;
                    } else {
                      return sliceLeft.start - sliceRight.start;
                    }
                  });

                  // select top N slices in content

                  var upperBound = parseInt('1');
                  if (upperBound >= 0) {
                    slicesOfContent = slicesOfContent.slice(0, upperBound);
                  }

                  // highlight title and content

                  function highlightKeyword(text, slice) {
                    var result = '';
                    var prevEnd = slice.start;
                    slice.hits.forEach(function (hit) {
                      result += text.substring(prevEnd, hit.position);
                      var end = hit.position + hit.length;
                      result += '<b class="search-keyword">' + text.substring(hit.position, end) + '</b>';
                      prevEnd = end;
                    });
                    result += text.substring(prevEnd, slice.end);
                    return result;
                  }

                  var resultItem = '';

                  if (slicesOfTitle.length != 0) {
                    resultItem += "<li><a href='" + articleUrl + "' class='search-result-title'>" + highlightKeyword(title, slicesOfTitle[0]) + "</a>";
                  } else {
                    resultItem += "<li><a href='" + articleUrl + "' class='search-result-title'>" + title + "</a>";
                  }

                  slicesOfContent.forEach(function (slice) {
                    resultItem += "<a href='" + articleUrl + "'>" +
                      "<p class=\"search-result\">" + highlightKeyword(content, slice) +
                      "...</p>" + "</a>";
                  });

                  resultItem += "</li>";
                  resultItems.push({
                    item: resultItem,
                    searchTextCount: searchTextCount,
                    hitCount: hitCount,
                    id: resultItems.length
                  });
                }
              })
            };
            if (keywords.length === 1 && keywords[0] === "") {
              resultContent.innerHTML = '<div id="no-result"><i class="fa fa-search fa-5x" /></div>'
            } else if (resultItems.length === 0) {
              resultContent.innerHTML = '<div id="no-result"><i class="fa fa-frown-o fa-5x" /></div>'
            } else {
              resultItems.sort(function (resultLeft, resultRight) {
                if (resultLeft.searchTextCount !== resultRight.searchTextCount) {
                  return resultRight.searchTextCount - resultLeft.searchTextCount;
                } else if (resultLeft.hitCount !== resultRight.hitCount) {
                  return resultRight.hitCount - resultLeft.hitCount;
                } else {
                  return resultRight.id - resultLeft.id;
                }
              });
              var searchResultList = '<ul class=\"search-result-list\">';
              resultItems.forEach(function (result) {
                searchResultList += result.item;
              })
              searchResultList += "</ul>";
              resultContent.innerHTML = searchResultList;
            }
          }

          if ('auto' === 'auto') {
            input.addEventListener('input', inputEventFunction);
          } else {
            $('.search-icon').click(inputEventFunction);
            input.addEventListener('keypress', function (event) {
              if (event.keyCode === 13) {
                inputEventFunction();
              }
            });
          }

          // remove loading animation
          $(".local-search-pop-overlay").remove();
          $('body').css('overflow', '');

          proceedsearch();
        }
      });
    }

    // handle and trigger popup window;
    $('.popup-trigger').click(function(e) {
      e.stopPropagation();
      if (isfetched === false) {
        searchFunc(path, 'local-search-input', 'local-search-result');
      } else {
        proceedsearch();
      };
    });

    $('.popup-btn-close').click(onPopupClose);
    $('.popup').click(function(e){
      e.stopPropagation();
    });
    $(document).on('keyup', function (event) {
      var shouldDismissSearchPopup = event.which === 27 &&
        $('.search-popup').is(':visible');
      if (shouldDismissSearchPopup) {
        onPopupClose();
      }
    });
  </script>





  

  

  

  

  
  

  

  

  

  

</body>
</html>
